Methods for controlled cultivation of microorganisms on the surface of gelled media are in widespread use. Techniques have been developed to study bacteria, fungi, mosses, and eukaryotic cells and tissues. Gelled media are also used in environmental microbial testing.
Awareness of environmental hazards has led to an increased desire to conduct microbial testing, and microbial test kits are available for such testing. For practical microbial field testing, it has become necessary to conduct such testing without the use of heating and/or laboratory sterilization of culture media in the field, and without the use of equipment such as autoclaves, glove boxes, or biological hoods in the field.
Agar is a commonly utilized gelling material for microbial culturing in Petri dishes and the like. Agar is derived from algae and includes a mixture of the polysaccharide agarose together with agaropectin. Agar has been used for many decades to solidify nutrient-containing growth media used for culturing and identifying different species of bacteria, yeasts and molds. A suspension of agar powder in liquid nutrient medium is typically boiled to dissolve the constituent polysaccharides, sterilized, and then cooled to approximately 50-60° C. before pouring the liquid medium into a culture container such as a glass or polystyrene Petri dish. The preparation of a sterile agar Petri dish typically requires specialized skill in sterile techniques and in preparation of the agar or other suitable growth media.
The availability of simplified and more rapid preparation methods for gelled culture media would improve the convenience and utility of microbial testing in the field such as in residential homes, manufacturing facilities and businesses, especially when performed by persons without specialized skills or equipment.